The field of the invention relates generally to the protection of a CCD video camera.
In recent years, the need for small, lightweight video cameras has rapidly developed in both the medical and industrial fields. One medical application requiring such a video camera is laparoscopy wherein an endoscope typically having a diameter of 5 to 10 mm is passed through a small incision in the patient to permit viewing of the surgical site. Earlier laparoscopic procedures required the surgeon to view the body cavity directly through the endoscope eyepiece. Now, a camera head may be attached to the endoscope eyepiece and a flexible cable typically connects the camera head to the remaining camera electronics at a remote location which are attached to a video monitor. This surgical visualization system allows the surgical team to view the interior of a body cavity on the monitor.
The surgical visualization system typically comprises components such as the endoscope, illumination light fiber bundle, coupling optics (i.e., couples the camera and endoscope) and camera head. Typically, the camera head contains an imager or charge-coupled device ("CCD") which receives the surgical site image from the coupling or other optics and transmits the image to associated electronics in preparation for video display. Because the surgical visualization components are used within a sterile field (i.e., an arbitrary area around the surgical site in which everything is sterile) in the operating room, they must be sterilized like other surgical instruments. Several sterilization procedures have been used in the past.
The steam autoclaving process wherein the instrument is inserted into a steam autoclave for approximately 45 minutes, is used for instruments that can withstand the high temperature for the necessary amount of time. Instruments which cannot withstand the autoclave process such as a camera head including a CCD are treated by less effective means which disinfect but do not sterilize, such as the cold soak process or by ethylene oxide gas exposure. A third alternative suitable for a camera head including a CCD is to apply a disposable sterile plastic cover over the camera head which remains in place during surgery. This alternative is also less effective because there is still a non-sterilized instrument within the cover which could infect the surgical site if the cover is punctured or falls off. Furthermore, the surgical instrument may become difficult to manipulate due to the cover's presence. Still further, because the cover is disposable, its cost is incurred for each surgical procedure.
Recently, short exposure steam sterilization, or flash sterilization, has been developed to sterilize instruments so that they may be immediately used. Flash sterilization may reduce the steam autoclave time of 45 minutes to less than five minutes but still involves increased temperatures. In any event, the advent of increasingly virulent contaminants which may not be eliminated by techniques which only disinfect but do not sterilize, and the need to quickly prepare instruments between surgical procedures has made flash steam sterilization the method of choice for many surgical instruments.
Flash sterilizable versions of all the surgical visualization components listed above currently exist except for the camera head including the CCD. Typically the CCD would be damaged or otherwise degraded if exposed to sterilization temperatures thereby rendering the CCD useless when later operated to view a surgical site. As a result, this generally requires that the camera head be disinfected with the less effective means set forth above or that a protective cover be used. Accordingly, there is a need for an apparatus containing a CCD which may protect the CCD from the increased temperatures present during flash sterilization.
An industrial application requiring a small video camera or CCD involves observation of high-temperature industrial processes such as those occurring in nuclear power generating stations, furnaces or engine compartments. Here, the CCD operates to observe the high-temperature process as it occurs. As in medical sterilization, the CCD would be damaged or its picture degraded if it were exposed to the increased temperatures associated with such industrial processes. Accordingly, there is a need for an apparatus containing a CCD which may protect the CCD from the increased temperatures associated with high-temperature industrial processes.
In addition to protection from heat which arises during medical or industrial applications, the CCD should be situated in the camera head or apparatus so that it is shielded from electromagnetic interference as well as from gas, water and other contaminants. Accordingly, there is a need for an apparatus which provides such protection.